Can dogs eat walnuts? It's best not to. A single shelled English walnut from the store is unlikely to poison a healthy dog, but walnuts are large, very fatty and easy to swallow whole. The serious danger is moldy walnuts and black walnuts, often found on the ground in yards and parks, which can carry toxins that cause tremors and seizures.
Better avoided. One fresh, plain store walnut usually means an upset stomach at most. Black walnuts, walnuts from the ground, moldy nuts, shells and hulls can be dangerous. If your dog ate any of those and starts trembling, call your vet right away.
Table of Contents
Why Walnuts Are Risky for Dogs
| Walnut type | Risk | Main concern |
|---|---|---|
| Fresh English walnut, shelled, plain | Low to moderate | Fat, size, stomach upset |
| Salted, candied or spiced walnuts | Moderate | Salt, sugar, seasonings |
| Moldy walnuts (any type) | High | Tremorgenic mycotoxins |
| Black walnuts, nuts and hulls | High | Mold toxins and GI irritation |
| Shells | Moderate to high | Choking, cuts, blockage |
- Fat: walnuts are about 65% fat. One walnut half has roughly 13 calories, and a handful can trigger vomiting, diarrhea or pancreatitis. Values are from USDA FoodData Central.
- Size and shape: whole walnuts can lodge in a small dog's throat or intestines.
- Mold: walnuts that sit damp on the ground often grow molds that produce tremorgenic mycotoxins, which can cause tremors and seizures.
Black Walnuts and Fallen Nuts
Black walnut trees are common across the eastern and central United States. Black walnut is listed as toxic to dogs, and its moldy nuts and hulls can cause tremors and seizures, according to the ASPCA. The hulls rot quickly and are a prime spot for mold. Dogs that chew or swallow them can develop vomiting, drooling and, if mold toxins are involved, tremors and seizures.
If you have walnut trees nearby, rake up fallen nuts and hulls during autumn, and keep your dog on a leash in parks where they drop.
Tremors after eating walnuts are an emergency. Signs of mycotoxin poisoning can start within 30 minutes to a few hours: vomiting, panting, restlessness, muscle tremors, wobbly walking, a high temperature and seizures. Call your vet or a poison control line right away and bring a sample of what your dog ate if you can do so safely.
My Dog Ate Walnuts. What Now?
- One or two fresh, plain store walnuts: watch for vomiting or loose stool over the next day. Most dogs are fine.
- A handful or a bag: call your vet, especially for small dogs or dogs with a history of pancreatitis.
- Black walnuts, ground walnuts or anything moldy: call your vet now, even before signs appear.
- Walnuts in shells: call your vet if your dog is gagging, vomiting, straining or not eating.
Don't try to make your dog vomit at home unless your vet tells you to.
Walnut Foods to Keep Away
- Banana bread and zucchini bread with walnuts: sugar, and sometimes raisins or chocolate chips.
- Brownies and cookies with walnuts: chocolate is toxic. See dog ate chocolate.
- Candied or maple walnuts: sugar and fat.
- Salads with walnuts: often with dressing, onion and dried cranberries.
- Walnut oil: pure fat.
How Walnuts Compare to Other Nuts
No nut is a great dog treat. Macadamia nuts are toxic, pecans carry the same mold concerns as walnuts, and almonds, cashews and pistachios are high in fat. See our macadamia, pecans and almonds guides. If your dog loves a nutty flavor, a dab of plain, xylitol-free peanut butter is a much safer choice.
Crunchy Swaps
- Carrot sticks or baby carrots, cut for small dogs
- Green beans, plain
- Apple slices without seeds
- Homemade dog biscuits
Is one walnut an emergency? A single fresh, plain store walnut usually isn't. Moldy walnuts, black walnuts or nuts from the ground are different, so call your vet for those.
What signs should send me to the vet right away? Tremors, twitching, wobbly walking, panting with restlessness, or seizures after eating walnuts. These need urgent care.
— Dr. Sarah Miller, DVM
Walnuts and Dogs: Quick Safety Guide
✕ Risky
- Black walnuts and their hulls
- Walnuts from the ground or moldy nuts
- Walnut shells
- Candied walnuts and walnut baked goods
✓ Better swaps
- Carrot sticks
- Plain green beans
- Apple slices without seeds
- Xylitol-free peanut butter
Call your vet right away if your dog ate moldy or black walnuts, or shows tremors.
Frequently Asked Questions
Are walnuts toxic to dogs?
Fresh English walnuts aren't considered toxic, but they're fatty and can cause stomach upset or blockage. Moldy walnuts and black walnuts can be truly dangerous.
Can dogs eat walnuts in banana bread?
A crumb is unlikely to hurt, but the bread is sugary and may contain chocolate or raisins. It's best not to share.
How many walnuts would make a dog sick?
It depends on the dog's size and the walnuts' condition. Even one moldy walnut can cause signs; a few fresh ones may just upset the stomach.
Can dogs eat walnuts and pecans?
Neither is a good choice. Both are fatty and can grow dangerous molds when they've been sitting outside.
My dog ate walnut shells. Is that bad?
Shells can scrape the mouth and gut or cause a blockage. Call your vet, especially if your dog is vomiting or not eating.
For more foods, browse the full what can dogs eat list.
The Bottom Line
Can dogs eat walnuts? It's best to skip them. Fresh store walnuts are fatty and hard to digest, and black walnuts, fallen nuts and moldy walnuts can cause tremors and seizures. Keep nuts out of reach, rake up walnuts in the yard, and call your vet right away if your dog ate any and starts trembling. More answers in our Can Dogs Eat…? library and the toxic foods list.
References & Sources
Written by CPD Nutrition Desk using the sources below. We are not affiliated with these organizations, and this guide is not a substitute for advice from your veterinarian.
- USDA — USDA FoodData Central
- ASPCA — Black walnut